Oil well blowout preventer



April 18, 1950 A. H. BELL OIL WELL BLOWOUT PREVENTER 2 Sheds-Sheet l Filed March 21, 1945 ATTORNEYS April 18, 1950 A. H. BELL on. WELL BLowouT PREVENTER 2 Sheets-Sheet 2 Filed March 2l, 1945 1 l nl Wil Patented Apr. 18, 1950 Alexander H. Bell, Los Angeles, Calif., assigner to Continental Oil Company, Ponca City, Okla., a corporation of Delaware Application March 21, 1945, Serial No. 583,998

'2 Claims.

This invention relates to blowout prevention devices for oil wells. During the various stages of drilling, production, or servicing of an oil well there are occasions when the pressure in the well is suflcient to force the contents of the well hole, whether it be oil, drilling mud, or the like, upwardly of the well. Means must, therefore, be provided for sealing oli' the well during such intervals. The occasions when it is necessary to do this may arise while the drill pipe is in the casing; while the tubing is in the casing; or While the casing is otherwise empty.

It is a principal object of my invention to provide a blowout prevention device which is effective to seal off the well under all of the aforementioned occasions.

It is a further object of my invention to provide a blowout preventer which is not only easy to operate but also is so constructed that the mud and other foreign matter in the well will neither interfere with its desired operation nor cause a fouling of any of the parts.

It is a further object of my invention to provide a blowout preventer of the character described which may also be used for the purpose of holding the drilling or tubing string during intervals when the same is being elevated or lowered into the well.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention maybe employed.'

In said annexed drawings- Fig. 1 is a broken side elevational view showing diagrammatically a well, its casing, and my blowout prevention device mounted on the casing;

Fig. 2 is a vertical section through the blowout preventer comprising my invention;

Figs. 3 and 4 are similar to Fig. 2 but show a different position of the valve members;

Fig. 5 is a part section, part elevational viewV of the parts as illustrated in Fig. 3 taken on a plane substantially indicated by the line 5 5; Fig. 6 is a transverse sectional view of the apparatus with the parts as illustrated in Fig. 4 taken on a plane substantially indicated by the line 6 6;

Fig. 7 is a sectional view of the apparatus as illustrated in Fig. 6 taken on a plane substantially indicated by the line 1 1;

Fig. 8 is a section view similar to Figs. 2, 3. and 4, but showing the valve members provided with gripping jaws in accordance with one modiiication of my invention;

Fig. 9 is a transverse section view of the structure illustrated in Fig. 8 taken on a plane substan tially indicated by the line 9 9;

Fig. 10 is a fragmentary sectional view drawn to an enlarged scale of one of the gripping jaws shown in Fig. 8; and

Fig. 11 is a partial elevational view of the upper face of the apparatus as illustrated in Figs. 5 and 6.

Referring now more specifically to the drawings and more especially to Fig. l, the device comprising my invention generally indicated at I is shown mounted on the upper end of a well casing 2 which is cemented into a rock formation as at 3 with the uncased well bore 4 extending downwardly into the earth with a drill bit 5 positioned on the lower end of a drill pipe i. In the usual drilling operation, -drilling mud would be circulated through the well bore by being pumped downwardly through the drill pipe 6 to rise in the well bore around the drill pipe .and to be discharged through the pipe 1.

The blowout preventer I comprises a main body portion 8 to which are bolted heads 9 provided with threaded holes into which the well casing may be threaded. The body 8 is provided with a substantially cylindrical passage I0 therethrough which is in axial alignment with the well casings. The body portion 8 is, itself, divided into two parts II and I2, the latter p serving as a cover and held to the main portion I I by means of a plurality of studs I3.

Rotatably mounted in the body 8 are valve members I4 and I5 each of which is provided with trunnions at opposite ends which are journalled in bearings provided therefor in the wall of the body. To one pair of trunnions there are keyed Worm gears I6 which are in mesh with worm pinions II keyed to a shaft I8 so that upon rotation of such shaft the valve members y Il and I5 are rotated in synchronism in opposite directions.

The valve members are generally cylindrical in form and rotate in close fitting openings ernbracing the outer periphery of the valve members. The valve members are mounted so that the cylindrical portions of their bodies are substantially tangent with the axes of the valve members lying on opposite sides of the axis of the passage IB and at substantially right angles thereto.

In the modication of the invention illustrated in Figs. 2. 3. and 4, the valve members are each provided with relieved portions I9, 20, and 2| so formed that when the valve members are in the position illustrated in Fig. 2 with the relieved portions I9 opposite each other, the valve members in no way obstruct the passage I0.

It will be observed that each of the relieved areas I9, 20, and 2| are semi-cylindrical in crosssection and complementary, i. e. the relieved areas I9 when opposite each other, as in Fig. 2, define a cylindrical passage equal for convenience to the diameter of the passage I0. The passages 20 when opposite each other denne a cylindrical opening having a diameter smaller than that defined by relieved areas I9 and the relieved areas 2i when opposite eachother define a cylindrical passage which is of still smaller diameter.

Extending axially of each of the valve members are a plurality of inserts 22. 29, 24, and 25. These inserts are positioned in axially extending slots and are formed of a compresslble gasket material such as synthetic rubber and in their normal state extend slightly radially outwardly of the edges of the slots in which they are contained. In actual practice it may be desirable to employ inserts which are cup-shaped in cross-section with the open face of the cup directed toward the source of pressure to be sealed off.

The operation of the device illustrated above is briefly as follows:

During the normal drilling operation when the drill pipe 9 extends downwardly into the casing and through the blowout preventer, the valve members will be in the position illustrated in Fig. 2. It will be observed that there are no pockets in the device in which the drilling mud may accumulate. When the casing contains no drill pipe or tubing and it is desired to shut oil the casing, then the valve members are rotated into the position illustrated in Fig. 3 with their unrelieved portions in engagement at the point of tangency between the valve members at which point there may be located one of the pairs of gasket members previously described.

When during the course of a drilling operation, and when a drill pipe 6 is in the casing, or when a similar tubing may be in the casing and it is desired to shut off the annular space between the casing 'and the pipe or tubing contained therein, then the valve members are rotated into the position illustrated in Fig. 4 with that pair of relieved portions opposite each other which will define a cylindrical passage equal to the outside diameter of the pipe or tubing in the casing. By having two pairs of relieved areas such as 20 and 2l of different sizes, the blowout preventer may be made to accommodate pipes or tubings of correspondingly different sizes.

In the modification illustrated in Figs. 8, 9, and l0, the valve members Ila and Ia are provided with relieved areas I9a and 20a which relieved areas when opposite each other respectively provide cylindrical passages which have the same diameter as the passage lila and the outside diameter of the tubing 6a respectively. At another axially extending area on the periphery of the valve members there are mounted jaws 26 which are held to the body B of the respective valve members by means of screw lugs 2l which pass through slotted openings 28 in the backs of the jaws. Each of the valve members preferably carries three such Jaws 26 as most clearly illustratedinFig.9andaslikewiseshowninsaid figure the rear faces or backs of the jaws are arcu- .ate so as to provide a rocking support between the jaws and the valve members as the laws are forced into engagement with the tubing Ia upon rotation of the valve members which carry the jaws.

The modification illustrated in Fig. 8 may be employed for the purpose of holding a string 0f tubing 6a while the same is released by the usual elevator. During the interval when the tubing string 6a is supported bythe blowout preventer as illustrated in Fig. 8, and a blowout of the well occurs, then the well may be sealed oil by having the elevator raise the string 6a slightly and by then rotating the valve members in the directions indicated by the arrows on Fig. 8 until the valve members around the relieved areas 20a engage the periphery of the tubing.

In order that the operator may determine at a glance the position of the valve members within the blowout preventer, the trunnions of one oi the valve members, as for example trunnion 29 in Fig. 6, carries on its outer end an indicating arm 30. Embossed or similarly placed on the outside of the casing, as shown in Fig. 1l, may be indicia opposite the various stages of the arm 30 denoting the condition of the valve members on the inside of the casing.

In addition to the axially extending sealing inserts I9, 20, and '2I, additional seals such as 9i may be arranged peripherally about the ends of the valve members.

As illustrated most clearly in Figs. 5 and 6, the axially extending sealing inserts such as 22, 23, 24, and 25 are preferably bonded at their ends to the circumferentially extending sealing inserts 3| in order to insure against leakage in the area where the two inserts join.

In the formation of the various relieved areas such as for example relieved areas I9, 20, and.v 2|, it must be kept in mind-that the leading edge of the relieved area with reference to the direction f of rotation of the valve member when such area is moved into operative position is at no greater distance from the center of rotation of the valve member or cylinder than is the active face of the relieved area. Otherwise, interference will occur in moving the valve members or cylinders into engagement with elements such as the pipe 9. The

foregoing can be accomplished by slightly tapering the forward end of each relieved area to the extent necessary.

Othermodes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

.1 I therefore particularly point out and distinctly claim as my invention:

l. In a device of the character described, the combination of a hollow casing having aligned openings in one pair of opposite walls to provide a passage therethrough, a pair of substantially cylindrical valve members journaled in the other pair of walls of said casing and provi'ded with complementary local relieved areas whereby at various positions of said valve members said passage is respectively substantially unobstructed, reduced to a smaller diameter, and closed off, the terminal portions of said valve members being of reduced diameter, annular projections on said casing having telescopic engagement with said reduced terminal portions. and flexible sealing means between said reduced terminals and said annular projections.

2. In a device of the lcharacter described, the combination of a hollow casing having aligned openings in one pair of opposite walls to provide a passage therethrough, a pair of substantially cylindrical valve members journaled in the other pair of walls of said casing and provided with complementary local relieved areas whereby at various positions of said valve members said passage is respectively substantially unobstructed, reduced to a smaller diameter. and closed off, the terminal portions of said valve members being of reduced diameter, annular projections on said casing having telescopic engagement with said reduced terminal portions, exible sealing means between said reduced terminals and said annular projections, means connecting said valve members providing synchronous rotation thereof, and

means projecting out of said casing for rotatingsaid valve members.

ALEXANDER H. BELL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Number 

